It was also probably easier to smell/taste beer and tell that it is safe. The scent of yeast fermentation is distinctive, and if contaminated before fermentati

It was also probably easier to smell/taste beer and tell that it is safe. The scent of yeast fermentation is distinctive, and if contaminated before fermentation the off scent can be quite apparent. So if receiving a liquid from an unknown/untrusted source, beer may have been safer than clear water.